LOG HEAVY. READ RAW.
Ditch the bloated apps. This is a collection of brutal, unstyled spreadsheets and calculators that just work. No accounts. No tracking pixels. Download the CSV, copy the logic, do the math.
The Calculators
1RM Calculator
Calculate your true one-rep max using Brzycki, Epley, and Lombardi formulas.
Plate Calculator
Determine exactly which plates to load on the bar.
Wilks & DOTS
Compare relative strength across weight classes.
RPE / RIR Targeter
Map your 1RM to specific RPE rep targets.
Volume Tracker
Calculate total session tonnage and tracking metrics.
Sinclair Coefficient
Olympic weightlifting relative strength calculator.
Open
Source
Iron
We don't sell subscriptions. We provide the raw CSVs and Google Sheets formulas for proven programs.
Browse Template IndexWHY RAW DATA?
Most fitness apps are built to retain your attention, not build your total. They lock your progression data behind paywalls, obscure the math behind proprietary "AI" readiness scores, and break when you don't have a signal in the basement.
A spreadsheet doesn't lie. A 1RM equation is just math. We host the tools statically. You take the numbers.
- 0 dependencies on external APIs
- All calculators work offline (JS)
- Templates are raw CSVs
STANDARD 1RM FORMULAS
| Author | Equation |
|---|---|
| Brzycki | Weight × (36 / (37 - Reps)) |
| Epley | Weight × (1 + 0.0333 × Reps) |
| Lombardi | Weight × Reps^0.10 |
* Formulations diverge significantly past 10 reps. Use carefully.